var DDSPEED = 10;
var DDTIMER = 15;
var doneCollapse = false;

function getAbsXMenu(obj) {
	//var obj=document.getElementById(elName);
	var leftOffset = 0;
	if (obj.offsetParent) {
	    while (obj.offsetParent) {
		 leftOffset += obj.offsetLeft;
		 obj = obj.offsetParent;
	    }
	} else if (obj.x) { //for NN4
	    leftOffset = obj.x;
	}
	return leftOffset;
}

function getAbsYMenu(obj){
	//var obj=document.getElementById(elName);
	var topOffset = 0;
	if (obj.offsetParent) {
	    while (obj.offsetParent) {
		 topOffset += obj.offsetTop;
		 obj = obj.offsetParent;
	    } 
	} else if (obj.y) { // for NN4
	    topOffset = obj.y;
	}
	return topOffset;
}

function tglMenu(id,d){
	ddMenu(id,1);
	cancelHide(id);
	ddMenu(id,d);
}

// main function to handle the mouse events //
function ddMenu(id,d){
	var h = document.getElementById(id + '-ddheader');
	var c = document.getElementById(id + '-ddcontent');
	var ifrm = document.getElementById(id + '-iframe');
	ifrm.style.top     = getAbsYMenu(c);
	ifrm.style.left    = getAbsXMenu(c);
	ifrm.style.width = c.offsetWidth;
	
	clearInterval(c.timer);
	if(d == 1){
		clearTimeout(h.timer);
		if(c.maxh && c.maxh <= c.offsetHeight){
			return
		} else if(!c.maxh){
			c.style.display = 'block';
			c.style.height = 'auto';
			c.maxh = c.offsetHeight;
			c.style.height = '0px';
		}
		c.timer = setInterval(function(){ddSlide(c,1,ifrm)},DDTIMER);
	} else {
		h.timer = setTimeout(function(){ddCollapse(c,ifrm)},50);
	}
}

// collapse the menu //
function ddCollapse(c,ifrm){
	c.timer = setInterval(function(){ddSlide(c,-1,ifrm)},DDTIMER);
}

// cancel the collapse if a user rolls over the dropdown //
function cancelHide(id){
  var h = document.getElementById(id + '-ddheader');
  var c = document.getElementById(id + '-ddcontent');
  var ifrm = document.getElementById(id + '-iframe');
  clearTimeout(h.timer);
  clearInterval(c.timer);
  if(c.offsetHeight < c.maxh){
    c.timer = setInterval(function(){ddSlide(c,1,ifrm)},DDTIMER);
  }
}

// incrementally expand/contract the dropdown and change the opacity //
function ddSlide(c,d,ifrm){
  var currh = c.offsetHeight;
  var dist;
  var ht;
  if(d == 1){
    ifrm.style.display='block';
    dist = (Math.round((c.maxh - currh) / DDSPEED));
  }else{
    ifrm.style.display='none';
    dist = (Math.round(currh / DDSPEED));
    if(dist <= 8) doneCollapse = true;
  }
  if(dist <= 1 && d == 1){
    ifrm.style.display='block';
    dist = 1;
  }
  
  ht = currh + (dist * d) + 'px';
  
  ifrm.style.height = ht;
  c.style.height = ht;  
  c.style.opacity = currh / c.maxh;
  c.style.filter = 'alpha(opacity=' + (currh * 100 / c.maxh) + ')';
  
  if((currh < 2 && d != 1) || (currh > (c.maxh - 2) && d == 1)){
    clearInterval(c.timer);
  }
}